Researchers Discover Fossils Of Winged Mammals From Dinosaur Age

First winged mammal fossil from Jurassic Period recovered in China

Millions of years ago, mammals used to glide from tree to tree by using their furry membranes of skin attached to their front and back limbs. Researchers have recently discovered fossil remains of two such flying creatures in eastern China and they lived alongside dinosaurs nearly 160 million years ago, making them the oldest-known winged mammals on record. The discovery suggests that winged mammals existed long before than researchers thought and the two specimens could provide new clues to the evolution of gliding animals.

“These Jurassic mammals are truly 'the first in glide. In a way, they got the first wings among all mammals,” said co-researcher Zhe-Xi Luo, a professor at the University of Chicago.

"With every new mammal fossil from the Age of Dinosaurs, we continue to be surprised by how diverse mammalian forerunners were in both feeding and locomotor adaptations. The groundwork for mammals' successful diversification today appears to have been laid long ago."

Many modern-day mammals, including flying squirrels and bats, exhibit remarkable ability to glide in the air. While many gliding mammalian fossils have been discovered over the years, the newly identified species are certainly the oldest ones. The larger species was about the size of North American flying squirrels. It has been named Maiopatagium furculiferum and it measures almost 10 inches long. The smaller creature, named Vilevolodon diplomylos, is just 3 inches long and weighed between 1 to 2 ounces. Given that both creatures "are quite old, they are considered to be long-extinct relatives of living mammals. Moreover, the fossils are so well preserved that paleontologists could actually see fur around their bodies. The fur and struture is similar to modern gliding squirrels.

"It's amazing that the aerial adaptions occurred so early in the history of mammals," said study co-author David Grossnickle from University of Chicago. "Not only did these fossils show exquisite fossilization of gliding membranes, their limb, hand and foot proportion also suggests a new gliding locomotion and behavior."

They primitive flying mammals fed on plants while their long limbs and fingers suggest that they gripped tree branches with their feet like a bat.

Jin Meng, a paleontologist at the American Museum of Natural History who was not involved in the study said. "These animals have much longer fingers, showing they have adaptations for grabbing on trees in the forest.”